I used to pay for them but no more.
For me, they never did work well. There are people whose business is based on PPC, and a few years past it was the most wide spread way to get traffic.
I never liked them and still don’t. Periodically I do go out and play some with them, but I surely would not spend money that I needed for other things, just mad-money.
With all the click fraud and with your esteemed colleagues clicking on your ad, I don’t see the bang for the buck.